A Massapequa man has admitted knowing his father was alive and well -- even as he filed a missing-person report and tried to cash in on a life insurance policy, prosecutors said in a criminal complaint filed Tuesday.

Jonathan Roth, 22, knew that his father -- feared drowned in the ocean on July 28 -- "was not missing because he observed him leave Jones Beach after informing the defendant that he was going to flee secretly to Florida," the complaint states.

Prosecutors also say Roth tried to collect on his father's MetLife insurance policy, valued at more than $50,000.

Judge Sondra K. Pardes of First District Court in Hempstead, remanded Roth on $5,000 cash bail or $10,000 bond.

Roth pleaded not guilty Tuesday to second-degree insurance fraud and fourth-degree conspiracy, both felonies; and to falsely reporting an incident and making a false written declaration, both misdemeanors.

Lenard Leeds, the Carle Place attorney representing Raymond Roth's wife, Evana, 45, of Massapequa, said he learned last week that Raymond Roth, who recently lost his job, tripled the value of his life insurance policy in January.

Leeds said his client, rocked by the revelations, has filed for divorce and "is trying to put her life back together."

Jonathan Roth told Newsday on Saturday that he thought his father had drowned. "I had no idea about this plan, this plot, whatever you want to call it," he said.

His girlfriend, Kristi Mayleas, 22, said she and Roth went to the Nassau district attorney's office in Mineola on Monday to pick up the cellphone he had turned over to investigators. He was arrested when he got there, much to his shock, she said.

Raymond Roth was presumed drowned for days until his brother called police last Wednesday to say Roth was in Orlando, Fla., where he has a time share. The same day, an officer in Santee, S.C., gave Roth a speeding ticket.

After learning of the incident, police contacted Roth and asked him to turn in his gun and pistol permit, said Sgt. Sal Mistretta, commanding officer of the department's Pistol License section. Mistretta said the permit was suspended because Roth is being investigated on a harassment charge in the city, and also because he allegedly took his pistol into New York City, where he's not allowed to possess a gun.